Hi,
As mentioned by IL earlier, there is info on the Forum relating to the Corps of Cattle Rangers. There is also a short book (perhaps booklet, with a roll) written by Lt Col Neil C. Smith, titled "The Corps of Cattle Rangers: Boer War 1899 - 1902".
This reference indicates that the official reason for the establishment of the unit was to provide protection and safe conduct of captured / commandeered Boer livestock. Interestingly it is mentioned in the book that the Cattle Rangers were not part of any tactical unit, formation or columns, rather receiving guidance from the Department of Supplies, acting on behalf of the Army Service Corps.
It seems that the combination of these arrangements and, as an incentive, compensation/ commission on the number of cattle delivered for slaughter, led to some rather "interesting" practices.
